1. Field of the Invention
The present invention relates to an optical connector. More particularly, the invention relates to an optical connector that connects fiber optic cables to each other, or to an optical element.
2. Description of Background Information
A fiber optic cable includes a plurality of optical fibers surrounded by a coating.
Japanese Publication No. SHO 58-42811 discloses an optical connector for holding such an fiber optic cable. The optical connector has a ferrule with protrusions on its inner cylindrical surface proximal to the end which connects to the main frame. Tightening the ferrule fixes the fiber optic cable to the connector. However, this tightening requires the application of considerable force, which compresses the optical cables; this compression results in an optical loss in transmission along the cable. While the application of less force reduces the optical loss, it also reduces the gripping strength of the ferrule.
In an optical connector disclosed in Japanese Publication No. HEI 2-29010, a pair of opposing sidewalls gradually enlarges toward an open end. The internal surfaces ofthese side walls have a plurality of undulating projections. The fiber optic cable is passed between the two sidewalls and held by tightening them. However, this tightening results in the same type of optical loss as discussed above.
Another optical connector, disclosed in Japanese Publication No. HEI 5-59412, has a clamp made of a thin metal sheet to form a channel having an U-shaped cross-section. The channel is pushed onto the fiber optic cable to cut into the cable coating to hold the optical cable. In this case, the width of the U-channel is slightly smaller than the diameter of the cable while the sidewalls of the U-shaped channel gradually enlarge from its closed end toward its open ends. When the optical cable is inserted into the U-shaped channel, the open ends cut into the cable coating, and the U-shaped channel is then thrust onto the coating. However, the clamp is small and made of a thin metal sheet. Consequently, the connector cannot be mounted easily, and may deform during mounting. Furthermore, as the open ends of the U-shaped channel forcibly cut into the cable coating, compression from the gradually decreasing width between the sidewalls of the U-shaped channel unavoidably distorts the optical fibers.